The optimization problem in (REF ) can readily apply quadratic transformation for multi-dimensional and complex FP [1]}, where the objective function is recasted as in (REF ),
where \(\mathbf {y} = \lbrace y_{u,q} | (u, q) \in \mathcal {U} \times \mathcal {Q} \rbrace \)  is the vector of auxiliary variables, and its optimal value is found as
\(y_{u,q}^{\ast } = \frac{z_{u,q}| \mathbf {h}_{u, q}^{\dagger }\mathbf {w}_{u,q}|^2\sqrt{ (1 + \gamma _{u, q})}}{\sum _{(i,j)} z_{i,j}| \mathbf {h}_{u,j}^{\dagger }\mathbf {w}_{i,j}|^2}. \) 
